The vice president of the union that represents all 17,000 nonsupervisory U.S. Border Patrol agents said Thursday that federal prosecutors spent “thousands of man-hours and millions of tax dollars” to win a two-year prison sentence for an agent accused of using excessive force on a drug-smuggling suspect.

Shawn P. Moran, himself a veteran Border Patrol agent, said the National Border Patrol Council (NBPC) disagreed with the “exorbitant waste of time and resources” devoted to the prosecution of Agent Jesus E. Diaz Jr., sentenced last week in U.S. District Court in Texas to 24 months in prison for depriving a 15-year-old suspect of his constitutional rights under color of law.

Mr. Moran said the case against Diaz “continues the tradition of bias against Border Patrol agents in the Western District of Texas,” where the U.S. attorney’s office also prosecuted Border Patrol Agents Ignacio Ramos and Jose Compean in 2006 after they shot a drug-smuggling suspect, Osvaldo Aldrete-Davila, in the buttocks as he tried to flee back to Mexico after abandoning a van filled with 800 pounds of marijuana.

Ramos and Compean, who claimed they were acting in self-defense, were convicted and sentenced to 11 and 12 years in prison, respectively. President George W. Bush commuted the sentences in 2009 after they had served two years.

“While the U.S. attorney’s office in the Western District of Texas has a job to do, one that includes prosecuting Border Patrol agents who commit crimes, it has shown a distinctly quick trigger finger in going after Border Patrol agents,” Mr. Moran said.

“That same quickness would be better served in prosecuting the criminals who routinely assault Border Patrol agents and violate the immigration and drug laws of the United States,” he said, adding that “thousands of man-hours and millions of tax dollars were spent to obtain a 24-month sentence for someone who had already spent eight months in custody.”

Diaz was named in a November 2009 federal grand jury indictment with deprivation of rights under color of law during an October 2008 arrest near the Rio Grande in Eagle Pass, Texas, where agents had responded to a report that illegal immigrants had crossed the river with bundles of drugs. He was convicted on one count of excessive force and five counts of perjury.

The prosecution had been sought by the Mexican government, with the Mexican consulate in Eagle Pass sending a formal written complaint just hours after the arrest, alleging that the teenager had been beaten.

Defense attorneys argued there were no injuries or bruises on the suspected smuggler’s lower arms where handcuffs had been placed nor any bruising resulting from an alleged knee on his back. Evidence presented at trial showed the only marks on his body came from the straps of the pack he carried containing the suspected drugs.

Border Patrol agents found more than 150 pounds of marijuana at the arrest site. The defense claimed that the smuggling suspect was handcuffed after becoming uncooperative and resisting arrest, and that Diaz had lifted the teenager’s arms to force him to the ground - a near-universal police technique.

The charges against Diaz, 31, a seven-year Border Patrol veteran, had been investigated by Homeland Security’s Office of Inspector General and U.S. Immigration and Customs Enforcement’s Office of Professional Responsibility, which cleared the agent of any wrongdoing. The Internal Affairs Division at U.S. Customs and Border Protection ruled differently nearly a year later and the agent was charged.

Mr. Moran said Diaz’s actions in the arrest did not rise to the level of a crime, and that the accusations should have been dealt with at the administrative level - resulting at most in his termination.